A 3D electronic module is a stack of heterogeneous electronic components. The term “heterogeneous component” is understood to mean an electronic component comprising at the same time one or more active and/or passive components connected together and thus forming an electronic circuit ensuring a given electronic function. The active component comprises any component usually called a “chip” and employing semiconductor technology; it may for example be a diode, a transistor, an integrated circuit, a dedicated ASIC circuit, a memory or a microprocessor. The term “passive component” is understood to mean the other components, whether these be conventional surface-mounted components of the resistor, capacitor or inductor type, or electromechanical components etched into the silicon and known as MEMS (microelectromechanical systems).
The term “vertical interconnection” is understood to mean interconnection in the stacking direction.
There are many techniques for interconnecting 3D electronic modules, which may be divided into two families:                interconnection and stacking of heterogeneous components;        interconnection and stacking of silicon wafers each comprising a multitude of identical heterogeneous components.        
The invention relates to the vertical interconnection of such wafers.
According to a known technique, these wafers are interconnected by means of vias, i.e. holes passing through the wafer in its thickness direction, which are electrically isolated therefrom and then metallized. The components are connected to the vias. The interconnection of metallized vias is tricky, and is based on the following methods:                thermocompression bonding;        solder alloy reflow;        etc.        
In general, these methods require:                high-temperature treatments and/or pressure on each interconnect which damage a not insignificant number of components;        extremely precise alignments difficult to achieve; and        very good flatness, as all the vias must be contacted.        
In addition, the 3D modules obtained are individually checked, but the quality of the interconnects is not.